Watch List notes:

Constantine I the Great AD 307-337, Cyzicus Mint, ca. AD 328-329.
Diademed head of Constantinus I right, CONSTANTINVS AVG;
Campgate with two turrets and star between them, PROVIDENTIAE AVGG, in exergue SMK__
RIC VII 55. Beautiful piece. Extremely fine. Size: D: 19.4mm; 3.35g